“Spying among friends cannot be,” German Chancellor Angela Merkel said Thursday in her first public comments since allegations emerged that U.S. intelligence may have been monitoring her cell phone.

“We need trust among allies and partners,” Merkel said as she arrived to a European Union summit in Brussels. “Trust now has to be built anew. This is what we have to think about.”

The U.S. Embassy declined to comment on Merkel’s statement, but the Obama administration has denied that it is monitoring Merkel’s communications, the Associated Press reports, though stopped short of addressing any possible past monitoring.